A voltammetric immunosensor for clenbuterol based on the use of a MoS₂-AuPt nanocomposite

An ultrasensitive immunosensor for the direct detection of the illegally used livestock feed clebuterol (CLB) is described. It is based on the use of a glassy carbon electrode modified with an MoS₂-AuPt nanocomposite and on biotin-streptavidin interaction. The use of MoS₂-AuPt accelerates electron transfer, and this leads to a sharp increase in the electrochemical signal for the electrochemical probe hydrogen peroxide. Differential pulse voltammetry was used to record the current signal at a peak potential of -0.18 V (vs SCE). Under optimal conditions, the electrode has a linear response in the 10 pg·mL^-1 to 100 ng·mL^-1 CLB concentration range and a 6.9 pg·mL^-1 detection limit (based on the 3σ criterium). This immunosensor is sensitive, highly specific and acceptably reproducible, and thus represents a valuable tool for the determination of CLB in pork. Graphical abstract Schematic of a voltammetric immunosensor for the determination of clenbuterol (CLB) based on the use of a nanocomposite prepared from molybdenum disulfide and a gold-platinum alloy (MoS₂-AuPt), and making use of the biotin-streptavidin system.